Drill Press Chucks
The chucks supplied with most tradesman drill presses can have a relatively high total indicated readout (TIR) & marginal gripping power. I upgraded all my drill presses with Made in the USA, Jacobs chucks. Shown is a Jacobs taper (JT-33), heavy duty, 0" ~ ½" (0mm ~ 13mm), keyed chuck on a bench drill press. The extra large jaws & key, coupled with high quality, totally eliminates any drill bit slippage. Shown with a Dewalt split-tip ¼" jobbers drill bit.
Also shown is the replacement chuck for a floor-standing, 16 speed, 16.5" swing, Jet drill press. The low, 200 RPM speed is good for the drilling larger holes. Its uses a removable MT-2 (Morse taper) to JT-3 chuck arbor. This type of arbor arrangement allows the mounting of a Jacobs ball bearing Super Chuck, ⅛" ~ ⅝" (3mm ~ 16mm). The low-cost chuck arbors come in a large number of size combinations allowing one to adapt almost any chuck to a given spindle. For example, I obtained an MT-2 to JT-33 arbor (Enco) to allow mounting the smaller Jacobs chuck since it can hold smaller drill bits in the range of 0" ~ ⅛" (0mm ~ 3mm). Use the proper cutting fluid when drilling metals.
CAUTION: Always clamp
the piece to the table before drilling. Do not hold by hand.
Standard drills will grab soft metals like brass, lift the
work piece,
even with a small vise, and dangerously spin them at high speed. Clamp or
bolt down the piece.
Make sure the drill press table is locked onto the column, too.
Using a mill with fine down feed is a better method to drill soft metals.
I made an adjustable work-stop peg that fits into the table slot.
The Jacobs Super Chuck is of superior quality having low a TIR & the ball bearing design allowing very high gripping power.
The picture shows a ViseGrip drill press hold down clamp. A Royal micro-sensitive feed attachment with a Jacobs JT0 keyed chuck (0" ~ 5/32") for small hole drilling (from Enco). Its straight shank is ½" in diameter; overall drill travel is ¾". Use the highest RPM. Hold the aluminum ring between your fingers (it is mounted in a ball bearing to decouple it from the rotating shaft) & apply downward pressure. It has far less drilling pressure than the drill press rack & pinion. An internal spring that retracts the chuck.
Drill bits, reamers & counter bores.
